An Alternative Splicing Product of the Lamin A/C Gene Lacks Exon 10

doi:10.1074/jbc.271.16.9249

An Alternative Splicing Product of the Lamin A/C Gene Lacks Exon 10 (*)

From the Department of Molecular Cell Biology and Genetics, University of Limburg, Maastricht, The Netherlands

^§To whom correspondence should be addressed:
Dept. of Molecular Cell Biology and Genetics, University of Limburg, P. O. Box 616, 6200 MD Maastricht, The Netherlands.
Tel.: 31-433881366/1351; Fax: 31-433670948.

Abstract

Expression of the A-type lamins was studied in the lung adenocarcinoma cell line GLC-A1. A-type lamins, consisting of lamin A and C, are two products arising from the same gene by alternative splicing. Northern blotting showed in GLC-A1 a relatively low expression level of lamin C and an even lower expression level of lamin A as compared to other adenocarcinoma cell lines. Immunofluorescence studies revealed highly irregular nuclear inclusions of lamin A, suggesting protein or gene expression abnormalities. Reverse transcriptase-polymerase chain reaction-based cDNA analysis followed by sequencing indicated the presence of an as yet unidentified alternative splicing product of the lamin A/C gene. This product differs from lamin A by the absence of the 5′ part of exon 10 (90 nucleotides). Therefore we propose to designate this product lamin AΔ10. Deletion of the 30 amino acids encoded by exon 10 was predicted to result in a shift in pI of the protein from 7.4 to approximately 8.6, which was confirmed by two-dimensional immunoblotting. mRNA analysis in a variety of cell lines, normal colon tissue as well as carcinomas demonstrated the presence of lamin AΔ10 in all samples examined, suggesting its presence in a variety of cell types.

Footnotes

↵* The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore by hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
↵¹ The abbreviations used are:

RT

reverse transcriptase

PCR

polymerase chain reaction

bp

base pair(s).
- Received July 24, 1995.
- Revision received January 16, 1996.